The Human Assessment and Biostatistical Core (HABC) will provide support to all projects in the Program Specifically, this support will include: 1) the screening and recruitment of human subjects for the clinic projects, 2) biostatistical consulting to all of the projects, 3,) statistical programming consulting to all of the projects, and 4) data analysis resources as needed. The Clinical Research Support Data Base (CRSDB) will continue to serve as a subject registry and research tool. Data are collected from all subjects registered for an initial visit to the multidisciplinary Penn Center for Sleep Disorders as well as from collaborating sleep centers. Data collected include patient demographics, subjective symptom reports, physician physical assessments, polysomnography results, final diagnosis, and treatment modalities. The CRSDB is available to all Program investigators interested in obtaining information on the relationships among collected variables, prevalence of specific characteristics, etc. It is maintained on the VAX 4000 of the Clinical Research Center using the SAS statistical and data management software. The data can be accessed by way of modem by any Program investigator or the statistical programmer can respond to specific information requests. Currently, information on approximately 700 patients has been collected from 3 sleep centers (Penn, Hopkins, and West Penn in Pittsburgh). Research into the relationships among the variables included in the CRSDB was initiated by the director/biostatistician. This research will be extended. The Core will be staffed by a director/biostatistician, a nurse researcher, a statistical programmer, and data entry/collection personnel. The Core will work in close collaboration with physicians involved in patient care in the area of subject recruitment and in close collaboration with clinical physicians and other Program investigators in the area of its own research initiatives utilizing the CRSDB.